what volume of 4.50mol dm-3 HNO3 should be diluted with water to form 2.5dm3 of 1.20mol dm-3 nitric acid?

Which theory was contradicted by experiments with the photoelectric effect? light spreads out after it passes through a small opening. as soon as light strikes metal, electrons will be ejected. visible light, regardless of color, will cause the ejection of electrons when striking metal. the kinetic energy of ejected electrons depends on the frequency of light that strikes the metal.